HUANG Lihua, Fudan University
Session 6: Computer Hardware
PART I Introduction to the Foundation of Information
Technologies
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Management Challenges
1. The centralization versus decentralization debate.
2. The application backlog.
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Hardware components of a computer system
HUANG Lihua, Fudan UniversityFeb., - July., 2006
The Central Processing Unit (CPU)
• Controls other parts of computer
• Arithmetic-logic unit performs principle logical/mathematical operations
• Control unit coordinates other parts, such as reading a stored program
HUANG Lihua, Fudan UniversityFeb., - July., 2006
CPU & PRIMARY STORAGE
CPUCPUPRIMARYPRIMARY
STORAGESTORAGE
DATA BUS
ADDRESS BUS
CONTROL BUS
INPUT
DEVICES
OUTPUT
DEVICES
SECONDARY
STORAGE
HUANG Lihua, Fudan UniversityFeb., - July., 2006
CENTRAL PROCESSING UNIT (CPU)
RAMRAM
PRIMARY (MAIN) MEMORYPRIMARY (MAIN) MEMORY
CONTROL UNITCONTROL UNITARITHMETIC/LOGICARITHMETIC/LOGIC
UNITUNIT
ROMROMCLOCKCLOCK
HUANG Lihua, Fudan UniversityFeb., - July., 2006
计算机中的数据处理过程: 机器指令和机器周期
机器指令:
1 、取机器指令
2 、指令翻译 3 、把指令放到寄存器中
4 、把地址放到寄存器中
5 、把数据从内存中取到寄存器中
6 、命令 ALU 执行相应的操作7 、 ALU 执行操作
8 、把结果送到累加器中
指令周期
执行周期5.20
HUANG Lihua, Fudan UniversityFeb., - July., 2006
The CPU• CPU = Central Processing Unit• Instruction execution is automatic
– (tick) find memory address of next instruction– (tick) retrieve instruction from memory– (tick) decode the instruction– (tick) fetch argument from memory if necessary– (tick) execute instruction– (tick) store result in memory if necessary
• Internal clock ticks very fast (e. g., 100MHZ = 100 million ticks per second)– activities are synchronized to start on a clock tick– some activities take more than one clock tick
HUANG Lihua, Fudan UniversityFeb., - July., 2006
COMPUTER TIME
Millisecond .001 second thousand 15min 40 sec
Microsecond .001 millisecond million 11.6 days
Nanosecond .001microsecond billion 31.7 years
Picosecond .001 nanosecond trillion 31,700 years
NAME LENGTH SECOND TO 1 SECONDNAME LENGTH SECOND TO 1 SECOND
# PER COMPARED# PER COMPARED
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Primary Storage
• Located near CPU• Stores all or part of active software program• Stores operating system software• Stores data the program is using• Composed of semi-conductors• RAM (random access memory): Used for short-ter
m, temporary storage• ROM (read-only memory): Semiconductor memor
y chips with program instructions
HUANG Lihua, Fudan UniversityFeb., - July., 2006
TYPES OF MEMORY
• RAM: Random Access Memory– Dynamic: Changes thru processing
– Static: Remains constant (power on)
• ROM: Read Only Memory (preprogrammed)– PROM: Program can be changed once
– EPROM: Erasable thru ultraviolet light
– EEPROM: Electrically erasable
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HUANG Lihua, Fudan UniversityFeb., - July., 2006
The CPU and primary storage
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Microprocessors
• Semiconductor chips integrate memory, logic, and control circuits for entire CPU
• Speed depends on number of bits processed at one time; amount of data that can be moved between devices; and cycle speed (MHz)
• RISC (reduced instruction set computing) increases speed; used for scientific, workstation computing
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Secondary Storage Technology
• Used for relatively long-term storage of data outside CPU
• Magnetic disk: floppies, hard disks, RAID• Optical disk: CD-ROM, CD-RW, DVD• Magnetic tape• Storage networking: direct-attached storage; net
work-attached storage; storage area networks
HUANG Lihua, Fudan UniversityFeb., - July., 2006
STORAGE AREA NETWORK (SAN)
• HIGH-SPEED NETWORK• CONNECTS VARIOUS STORAGE
DEVICES– TAPE LIBRARIES– DISK ARRAYS
STORAGE SERVICE PROVIDER: 3rd party rents storage space
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HUANG Lihua, Fudan UniversityFeb., - July., 2006
A Storage Area Network (SAN)
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Input Devices
• Keyboard and mouse
• Touch screen
• Optical character recognition
• Magnetic ink character recognition (MICR)
• Pen-based input
• Digital scanner
• Audio input
• Sensors
• Radio-frequency identification (RFID)
HUANG Lihua, Fudan UniversityFeb., - July., 2006
POINTING DEVICES
• KEYBOARD• MOUSE
– WIRED– INFRA-RED– TRACKBALL– TOUCH PAD
• JOYSTICK• TOUCH SCREEN
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© 2002 by Prentice Hall
HUANG Lihua, Fudan UniversityFeb., - July., 2006
SOURCE DATA AUTOMATION
• Captures data in computer-readable form at the time and place the data are created
• OPTICAL CHARACTER RECOGNITION (OCR): translate designed marks, characters, and codes into digital form.– BAR CODE: Identifies products in stores, warehouses, shipments
• MAGNETIC INK CHARACTER RECOGNITION (MICR): translate characters written in magnetic ink into digital format– Special ink identifies bank, account, amount
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© 2002 by Prentice Hall
HUANG Lihua, Fudan UniversityFeb., - July., 2006
SOURCE DATA AUTOMATION
• PEN-BASED INPUT: Digitizes signature• DIGITAL SCANNER: Translates images &
characters into digital form• VOICE INPUT DEVICES: Converts spoken word
into digital form• SENSORS: Devices that collect data from
environment for computer input (e.g., thermometers, pressure gauges)
• *
© 2002 by Prentice Hall
HUANG Lihua, Fudan UniversityFeb., - July., 2006
OUTPUT DEVICES
• CATHODE RAY TUBE (CRT)
• PRINTER
• PLOTTER
• VOICE OUTPUT DEVICE
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HUANG Lihua, Fudan UniversityFeb., - July., 2006
CATEGORIES OF COMPUTERS
• Mainframe: – Largest computer; handles massive amounts of data;
used for large business, scientific, military applications• Midrange computer:
– Smaller, less expensive minicomputers or servers; used for smaller organizations or managing networks
• Minicomputers: – Used in systems for universities, factories, research labs
• Servers: – Manage internal company networks or Web sites
HUANG Lihua, Fudan UniversityFeb., - July., 2006
CATEGORIES OF COMPUTERS
• Personal computer: – Portable or desktop microcomputer
• Workstation: – More powerful desktop computer used for computatio
n-intense tasks
• Supercomputer: – Sophisticated, powerful computer used for tasks requiri
ng rapid, complex calculations; weapons research, weather forecasting
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Computer hardware trends
• Performance----better
• Price----lower
• Size----more compact
(1) The CPU
(2) Storage devices
(3) User Interfaces
(4) Type of PCs
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Computer Networks and Client/Server Computing
• Distributed processing: – Distribution of processing work among
multiple computers
• Centralized processing: – Accomplished by one large central computer
• Client/server computing: – Splits processing between “clients” and
“servers” on network
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Client/server computing
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Types of client/server computing
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Network Computers and Peer-to-Peer Computing
• Network computer (NC): – Simplified desktop computer, does not store data
permanently
• Peer-to-peer computing: – Distributed processing that links computers through
Internet or private networks
• Grid computing: – Applies computational resources of many networked
computers to solve a large, complex problem
HUANG Lihua, Fudan UniversityFeb., - July., 2006
Assignment for Session 7• Individual Preparation for session 7
– Reading Materials• Textbook: chapter 4
– P135. Review Quiz• Write down in your book, not submit
• Group Assignment: bring to class– Please design the software architecture for Mr.
Wang’s Pottery Company, including system software, application software.
– Prepare for the CASE QUESTIONS on P.121.